全文获取类型
收费全文 | 4462篇 |
免费 | 465篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 43篇 |
儿科学 | 124篇 |
妇产科学 | 132篇 |
基础医学 | 631篇 |
口腔科学 | 104篇 |
临床医学 | 526篇 |
内科学 | 1137篇 |
皮肤病学 | 77篇 |
神经病学 | 448篇 |
特种医学 | 118篇 |
外科学 | 476篇 |
综合类 | 108篇 |
一般理论 | 7篇 |
预防医学 | 414篇 |
眼科学 | 49篇 |
药学 | 257篇 |
中国医学 | 1篇 |
肿瘤学 | 286篇 |
出版年
2023年 | 52篇 |
2022年 | 47篇 |
2021年 | 119篇 |
2020年 | 88篇 |
2019年 | 120篇 |
2018年 | 112篇 |
2017年 | 84篇 |
2016年 | 97篇 |
2015年 | 91篇 |
2014年 | 149篇 |
2013年 | 182篇 |
2012年 | 281篇 |
2011年 | 263篇 |
2010年 | 188篇 |
2009年 | 159篇 |
2008年 | 211篇 |
2007年 | 249篇 |
2006年 | 241篇 |
2005年 | 224篇 |
2004年 | 212篇 |
2003年 | 168篇 |
2002年 | 151篇 |
2001年 | 99篇 |
2000年 | 103篇 |
1999年 | 116篇 |
1998年 | 74篇 |
1997年 | 48篇 |
1996年 | 46篇 |
1995年 | 51篇 |
1994年 | 41篇 |
1993年 | 45篇 |
1992年 | 85篇 |
1991年 | 59篇 |
1990年 | 60篇 |
1989年 | 55篇 |
1988年 | 49篇 |
1987年 | 64篇 |
1986年 | 36篇 |
1985年 | 40篇 |
1984年 | 44篇 |
1983年 | 31篇 |
1982年 | 19篇 |
1981年 | 24篇 |
1980年 | 21篇 |
1979年 | 25篇 |
1978年 | 30篇 |
1977年 | 25篇 |
1975年 | 18篇 |
1973年 | 15篇 |
1971年 | 18篇 |
排序方式: 共有4938条查询结果,搜索用时 15 毫秒
21.
We present a comprehensive, meta‐analytic review and critical evaluation of outcome research pertaining to the effectiveness of premarital prevention programs. Results revealed that the mean effect size for premarital programs was .80, which means that the average person who participated in a premarital prevention program was significantly better off afterwards than 79% of people who did not participate. Stated differently, the average participant in a premarital program tends to experience about a 30% increase in measures of outcome success. Our findings suggest that premarital prevention programs are generally effective in producing immediate and short‐term gains in interpersonal skills and overall relationship quality and that these improvements are significantly better than nonintervention couples in these areas. However, because of a lack of extended follow‐up research, conclusions about long‐term effectiveness remain elusive. We propose implications for future research, education, and policy. 相似文献
22.
D. J. King M. Blomqvist S. J. Cooper M. M. Doherty M. J. Mitchell R. C. Montgomery 《Psychopharmacology》1992,107(2-3):175-179
Sixty-two DSM III chronic schizophrenic inpatients were selected for a double-blind, placebo controlled, multi-centre, relapse prevention study of remoxipride, a selective dopamine (D2)-receptor antagonist. After a 1 month placebo washout, 23 patients had relapsed and were withdrawn. Of the remaining patients 19 were randomised to remoxipride (150–300 mg daily) and 20 to placebo. Their median age was 58 years, 26 were male, and the median duration of illness was 33 years. After 24 weeks a further total of 8 remoxipride and 17 placebo patients had been withdrawn. Excluding three patients withdrawn for reasons other than relapse, the comparative relapse rates were 37% and 75%, respectively (P=0.015). Efficacy analyses using clinical global impression (P=0.04) and change in BPRS scores (P=0.016) were in favour of remoxipride. Extrapyramidal symptoms were minimal in both groups. Treatment emergent adverse events were similar in the two groups. Remoxipride is therefore of potential value as a safe drug which is both effective and well tolerated in the long term management of chronic schizophrenic patients. 相似文献
23.
J. H. Brown A. P. Maxwell I. Bruce B. G. Murphy C. C. Doherty 《Irish journal of medical science》1993,162(6):213-217
Renal failure frequently complicates both multiple myeloma and systemic amyloidosis. Renal replacement therapy (RRT) may be poorly tolerated and its role in such patients is not clearly defined. Of fifty patients (26 males and 24 females) referred to a single centre because of renal failure associated with multiple myeloma or systemic amyloidosis 37 progressed to end-stage renal failure and 30 of these patients received RRT. Nine patients have been treated by CAPD, 13 by haemodialysis, and 8 patients have required both forms of dialysis. Overall one year and two year survival rates were 66 % and 57 % respectively. The median duration on RRT was 7.5 months (range 1–96 months) with a 51% one year, and a 46% two year survival rate. Of 7 patients with amyloidosis who underwent renal transplantation, 3 died within 6 months of transplantation. Undiagnosed cardiac involvement contributed to this early mortality. We conclude that renal replacement therapy is appropriate for some patients with multiple myeloma and systemic amyloidosis who develop endstage renal failure. Careful asssessment and selection of patients is necessary prior to renal transplantation. 相似文献
24.
N. S. Doherty R. J. Griffiths J. P. Hakkinen D. N. Scampoli A. J. Milici 《Inflammation research》1995,44(4):169-177
Intraperitoneal injection of inflammatory agents in the mouse and rat causes plasma protein and leukocyte extravasation into the peritoneal cavity. Following an intraperitoneal injection of zymosan A, the milky spots of the omentum were the only abdominal sites detected where intravenously administered Monastral Blue labeled interendothelial cell gaps responsible for plasma extravasation. In addition, when colored microspheres were intraventricularly administered to quantify blood flow, the omentum was the only abdominal organ which showed an increase in blood flow during zymosan A peritonitis. A combination of light and electron microscopy, plus measurement of myeloperoxidase activity (a marker of neutrophil accumulation) demonstrated that the omental milky spots are the major route through which leukocytes migrate into the peritoneal cavity. Identical structures in the pleura likewise are the sites of protein leakage into the pleural cavity. In contrast, selective sites of protein and cellular extravasation could not be detected in the synovial lining of the inflamed knee joint. 相似文献
25.
Eliot Siegel Georgina Groleau Bruce Reiner Thomas Stair 《Journal of digital imaging》1998,11(1):18-20
Radiographs are ordered and interpreted for immediate clinical decisions 24 hours a day by emergency physicians (EP’s). The Joint Commission for Accreditation of Health Care Organizations requires that all these images be reviewed by radiologists and that there be some mechanism for quality improvement (QI) for discrepant readings. There must be a log of discrepancies and documentation of follow up activities, but this alone does not guarantee effective Q.I. Radiologists reviewing images from the previous day and night often must guess at the preliminary interpretation of the EP and whether follow up action is necessary. EP’s may remain ignorant of the final reading and falsely assume the initial diagnosis and treatment were correct. Some hospitals use a paper system in which the EP writes a preliminary interpretation on the requisition slip, which will be available when the radiologist dictates the final reading. Some hospitals use a classification of discrepancies based on clinical import and urgency, and communicated to the EP on duty at the time of the official reading, but may not communicate discrepancies to the EP’s who initial read the images. Our computerized radiology department and picture archiving and communications system have increased technologist and radiologist productivity, and decreased retakes and lost films. There are fewer face-to-face consultations of radiologists and clinicians, but more communication by telephone and electronic annotation of PACS images. We have integrated the QI process for emergency department (ED) images into the PACS, and gained advantages over the traditional discrepancy log. Requisitions including clinical indications are entered into the Hospital information System and then appear on the PACS along with images and readings. The initial impression, time of review, and the initials of the EP are available to the radiologist dictating the official report. The radiologist decides if there is a discrepancy, and whether it is category I (potentially serious, needs immediate follow-up), category II (moderate risk, follow-up in one day), or category III (low risk, follow-up in several days). During the working day, the radiologist calls immediately for category I discrepancies. Those noted from the evening, night, or weekend before are called to the EP the next morning. All discrepancies with the preliminary interpretation are communicated to the EP and are kept in a computerized log for review by a radiologist at a weekly ED teaching conference. This system has reduced the need for the radiologist to ask or guess what the impression was in the ED the night before. It has reduced the variability in recording of impressions by EP’s, in communication back from radiologists, in the clinical follow-up made, and in the documentation of the whole QI process. This system ensures that EP’s receive notification of their discrepant readings, and provides continuing education to all the EP’s on interpreting images on their patients. 相似文献
26.
27.
28.
López JA Bioley G Turtle CJ Pinzón-Charry A Ho CS Vuckovic S Crosbie G Gilleece M Jackson DC Munster D Hart DN 《Journal of immunological methods》2003,274(1-2):47-61
Dendritic cells (DC) for cancer immunotherapy protocols are generated most commonly by in vitro differentiation of monocytes with exogenous cytokines (Mo-DC). However, Mo-DC differ in their molecular phenotype and function from blood DC (BDC). Clinical isolation of BDC has been limited to the use of density gradients, which result in low yields of variable purity. We have developed a DC enrichment platform, which uses the CMRF-44 (IgM) or CMRF-56 (IgG) monoclonal antibodies (mAb) to select BDC that express these antigens after a short overnight incubation. After culture of peripheral blood mononuclear cells (PBMC) in autologous/AB serum, biotinylated CMRF-44 was used to select DC in a single step immuno-magnetic bead procedure; this produced populations containing up to 99% CMRF-44(+) cells, including up to 67% CMRF-44(+) CD14(-) CD19(-) DC, from an initial starting population of approximately 0.5%. We observed consistent differences in the purities obtained from individual donors with a mean of 54% CMRF-44(+) cells (range 19-99%). Similar results were obtained using biotinylated CMRF-56 mAb, an antibody identifying a comparable population in cultured PBMC. We recovered an average of 54% and 66% of the available BDC in separations performed with the CMRF-44 and CMRF-56 mAb, respectively. The reproducibility of the procedure and the ability to perform it in a closed sterile system makes it suitable for clinical use. Larger scale preparations starting from apheresis derived PBMC will produce sufficient BDC for immunotherapy protocols. The purified BDC elicited strong allogeneic mixed leukocyte reactions and HLA classes II- and I-restricted antigen-specific primary immune responses. 相似文献
29.
Induction of Lyt-2+ cytotoxic T lymphocytes following primary and secondary Salmonella infection. 下载免费PDF全文
Investigations of the cytotoxic activity of T cells induced following one or two intraperitoneal doses of live Salmonella revealed that cytotoxicity was restricted to the Lyt-2+ T-cell subset and was enhanced following secondary infection with Salmonella. Initial studies using the lectin-dependent cellular cytotoxicity (LDCC) assay detected Lyt-2+ cytotoxic T cells in peritoneal cell suspensions of S. enteritidis 11RX (11RX)-infected mice, with the peak of activity occurring 5 days after infection. This did not correlate with the proliferative activity of these cells, which peaked 10-12 days after infection. Secondary challenge with 11RX or S. typhimurium C5 (C5) induced a rapid increase in the cytotoxic activity of Lyt-2+ peritoneal T cells and was detected even 21 days later. The antigen specificity of some of these cells was confirmed in cytotoxicity assays using P815 tumour cells infected with 11RX organisms as targets. No cytotoxic activity was detected in the spleen cell suspensions of infected (and normal) mice unless the cells were first activated by in vitro culture with concanavalin A (Con A). Both types of activated spleen cells showed LDCC but Salmonella-specific cytotoxic Lyt-2+ T cells were detected only in spleen cell (SC) cultures prepared from mice challenged with a second dose of Salmonella. 相似文献
30.
Protective effects of aspirin against acute myocardial infarction and death in men with unstable angina. Results of a Veterans Administration Cooperative Study 总被引:31,自引:0,他引:31
H D Lewis J W Davis D G Archibald W E Steinke T C Smitherman J E Doherty H W Schnaper M M LeWinter E Linares J M Pouget S C Sabharwal E Chesler H DeMots 《The New England journal of medicine》1983,309(7):396-403
We conducted a multicenter, double-blind, placebo-controlled randomized trial of aspirin treatment (324 mg in buffered solution daily) for 12 weeks in 1266 men with unstable angina (625 taking aspirin and 641 placebo). The principal end points were death and acute myocardial infarction diagnosed by the presence of creatine kinase MB or pathologic Q-wave changes on electrocardiograms. The incidence of death or acute myocardial infarction was 51 per cent lower in the aspirin group than in the placebo group: 31 patients (5.0 per cent) as compared with 65 (10.1 per cent); P = 0.0005. Nonfatal acute myocardial infarction was 51 per cent lower in the aspirin group: 21 patients (3.4 per cent) as compared with 44 (6.9 per cent); P = 0.005. The reduction in mortality in the aspirin group was also 51 per cent--10 patients (1.6 per cent) as compared with 21 (3.3 per cent)--although it was not statistically significant; P = 0.054. There was no difference in gastrointestinal symptoms or evidence of blood loss between the treatment and control groups. Our data show that aspirin has a protective effect against acute myocardial infarction in men with unstable angina, and they suggest a similar effect on mortality. 相似文献